Practise frequently with your learners. The beginning and end of lessons are often good times to practise mental arithmetic – maybe spend two or three minutes doing this.
Starter activities could include working out mental arithmetic questions as part of a quiz, an activity, etc. Make it into a game.
Do ask learners to say how they worked something out. They could tell their method to the person sitting next to them. Or they could tell their method to the class.
Validate mental calculations. Children will not see the point in having to write down a method of arithmetic for a calculation they can do in their head. Nor should they have to: mental calculation is a perfectly good way of working out the answers to number questions, so encourage its use.
OpenLearn - Teaching mathematics
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